Mechanical properties of BCN films deposited by dual cesium ion beam sputtering system

A study has been made on the formation of boron–carbon–nitride (BCN) thin films. The BCN thin films were synthesized using dual cesium ion beam sputtering system, which consisted of conventional magnetron sputter for carbon and boron sources and cesium flow system for negative ion generation. Nitrogen gas was introduced into argon plasma as a nitrogen source. Optimum process parameters were examined by the method of Taguchi L9 experiment. Hardness of BCN films was mainly affected by carbon sputtering power, working pressure and boron sputtering power in sequence. At the optimum process condition, the hardness and stoichiometry of BCN film were 30.6 GPa and BC0.9N0.7. From Fourier transform infrared spectroscopy results, it was found that the characteristics of the films had mixed with sp2 BN, BC and CN bonding. The tribological behaviors of BCN films have been investigated by ball-on-disk tribometer. It is found that the friction coefficient is directly related to the film hardness and process parameters.